Shearwater Perdix AI

[charlier]

I have the Perdix AI and have put around 50 dives on it.

Cons: the design of the transmitter is horrible - it looks too similar to the valve on the tank. Twice already helpful people have twisted my transmitter and blown the first stage open. I'm going to spray paint the transmitter and put a wrench and more o-rings in my travel bag.

Without commenting the external design of the transmitter, this issue has been discussed before on SB. Based on my experience, it is easy to mistakenly grab the transmitter rather than the tank valve. In particular, getting on a dingy or RIB in bumpy seas, the boat crew might grad the transmitter by accident. One solution is to attach a small 4"-6"' HP hose to the transmitter to the 1st stage. Search SB for similar threads and alternative solutions.

 

[wetb4igetinthewater]

Without commenting the external design of the transmitter, this issue has been discussed before on SB. Based on my experience, it is easy to mistakenly grab the transmitter rather than the tank valve. In particular, getting on a dingy or RIB in bumpy seas, the boat crew might grad the transmitter by accident. One solution is to attach a small 4"-6"' HP hose to the transmitter to the 1st stage. Search SB for similar threads and alternative solutions.

Put it in a short hp hose

 

[skelzer]

I have the Perdix AI and have put around 50 dives on it.

Pros: having GTR and SAC in realtime during the dive is *amazing*. 100% worth the price of admission. About 6 dives after installing my transmitter my SPG broke and started freeflowing. Haven't had a change to replace it and at this point I don't think I will.

Cons: the design of the transmitter is horrible - it looks too similar to the valve on the tank. Twice already helpful people have twisted my transmitter and blown the first stage open. I'm going to spray paint the transmitter and put a wrench and more o-rings in my travel bag.

Overall, AI is now 100% a permanent part of my gear. I probably won't use an SPG. I can't think of anything worse than just having to surface with a safety stop if things fail. At this point adding an SPG just adds another point of failure. If the transmitter goes underwater or the battery dies in my computer, these are not life threatening situations. Hell, as long as air isn't leaking I'm not even sure it'd cause me to abort the dive.

Nice, good heads up with transmitter design... when/if I get the AI, I'll be sure to paint it.

FYI, I recently had a Suunto transmitter flood. Unfortunately, they don't always stop transmitting when it happens. In my situation, it actually began reporting bad data and jumped my psi by 700. When I noticed something was off, I was at 120 ft... so I signaled to my wife and asked her to stay at arms length. 10 minutes later my air cut off and my computer still showed 700 psi remaining. Wasn't fun...

I like diving streamlined with only two hoses, so I'm not moving to a full-size SPG for backup. Instead I installed a mini/button SPG to my reg. Hollis, H2Odyssey, Trident, DGX. and OTG make them... sometimes called a pony SPG (fav is Hollis as it has a color coded gauge). I'm aware this isn't a perfect replacement to a full size SPG but it's a better compromise than having no backup at all. If my transmitter floods again or I notice anything unusual, I can roll my tank around to check the readout or signal to my wife to check the PSI.... and there's less fail points than a full size SPG and zero additional hose.

Either way, thanks for the AI road test. I'm waiting for Shearwater to upgrade AI firmware to read dual/synchronous GTR for sidemount... then I'm all-in on the AI upgrade.

 

[hazmat]

Just make sure that painting the transmitter won't affect its signal. I have no idea if it does or not.

 

[skelzer]

Just make sure that painting the transmitter won't affect its signal. I have no idea if it does or not.

Eesh... good point. Probably just paint the battery cap instead.

 

[travlbum]

Put it in a short hp hose

This is probably the best solution...

I'm aware this isn't a perfect replacement to a full size SPG but it's a better compromise than having no backup at all.

Well... no one seems to be worried about all these people diving with just one SPG. I've never seen anyone dive with two SPGs, so I'm not sure why using AI instead of SPG means I need a backup at all. There doesn't seem to be much data out there on comparative failure rates, but from what I can tell SPGs fail all the time. Every diver I know with any significant amount of experience has had one go out at one time or another for them or their buddy. Not to say that AI is better, but that failure of air gauges is relatively common and just not that big of a problem.

 

[skelzer]

This is probably the best solution...



Well... no one seems to be worried about all these people diving with just one SPG. I've never seen anyone dive with two SPGs, so I'm not sure why using AI instead of SPG means I need a backup at all. There doesn't seem to be much data out there on comparative failure rates, but from what I can tell SPGs fail all the time. Every diver I know with any significant amount of experience has had one go out at one time or another for them or their buddy. Not to say that AI is better, but that failure of air gauges is relatively common and just not that big of a problem.

Difference is that a flooded spg goes to zero psi. When my transmitter flooded it added 700 psi to the readout... which can lead to severely different outcomes if you aren't pacing correctly.

 

[travlbum]

Difference is that a flooded spg goes to zero psi. When my transmitter flooded it added 700 psi to the readout... which can lead to severely different outcomes if you aren't pacing correctly.

Well, sometimes. A friend had his SPG get stuck, so it showed 80bar even after he ran out of air. When mine failed the gauge still worked but was free flowing air out of the swivel joint.

With AI, I'll know that something is wrong immediately because my SAC/GTR will be out of whack.

 

[Alastor]

SPG stuck to a reading greater than zero happened two times to me in 15 years. It is because few salt water drops get into the body and salt crystals developed on the axle where the hand is attached. When pressure is released, they interpose into the gear teeth preventing the hand from returning to zero.
The second time I discovered it when disconnecting the regulators from the tank I noticed that the hand was not zeroed. Lightly knocking the gauge worked for a dive or two, then the crystals got too big to be dislodged and I changed the SPG.
I opened it to check what was wrong and discovered the point. There is no clue that some water entered between the glass and the body, probably a drop each dive.

 

[AJ]

Well, sometimes. A friend had his SPG get stuck, so it showed 80bar even after he ran out of air. When mine failed the gauge still worked but was free flowing air out of the swivel joint.

With AI, I'll know that something is wrong immediately because my SAC/GTR will be out of whack.

Your friend should have known something was wrong when the SPG needle did not move. Check every 5 minutes, so you have max. 5 to 10 minutes before knowing something is wrong and abort. SPG needle getting stuck is no excuse for running out of air, sorry

As far as I'm concerned, it does'nt matter which way you are able to check air supply, just check it regurlarly so you know when something is wrong. Mechanic or AI does not matter. Both can give wrong information.